Zika and the WHO: lessons learned from Ebola

THE World Health Organization’s (WHO) response to the Zika virus outbreak on the South American continent is indicative of lessons learned from Ebola, in the wake of criticism that was largely unfair, say Australian experts in global health.

Dr Sanjaya Senanayake, from the Australian National University’s College of Medicine, Biology and the Environment, and author of an editorial published in the MJA today, said the WHO response to Zika so far had been “hard to argue with”.

Dr Senanayake told MJA InSight that four criteria must be met for a PHEIC to be declared – the outbreak must have a serious public health impact; it must be unexpected; it must have the potential to spread; and it must have the potential to lead to travel and trade restrictions.

“It wouldn’t be hard to argue that Zika meets at least two of those criteria,” Dr Senanayake said.

“I think it’s quite reasonable what the WHO has done in terms of Zika so far. Ebola was really the reason they [moved on] Zika so quickly. They are keen to err on the side of caution.”

Professor Sharon Lewin, director of the Peter Doherty Institute for Infection and Immunity in Melbourne, told MJA InSight that “decisions on the declaration of a Public Health Emergency of International Concern are often made in an environment of imperfect data”.

“In regards to the response to the current Zika outbreak, WHO, through the declaration of a PHEIC, has prioritised the collection of evidence to inform the next stage of the response in addition to preventing transmission of the Zika virus. Both components are vital at this stage of the outbreak and such announcements are critical to the mobilisation of global resource.”

Dr Hill-Cawthorne told MJA InSight that those who had criticised WHO after the Ebola outbreak were forgetting the organisation’s roots.

“The WHO was set up as a policy-making body, acting to bring governments together. It was not seen as a primary outbreak response unit,” he said.

“It’s only since the SARS outbreak in 2002-2004, the 2009 flu pandemic and the Ebola outbreak that it’s been given that title. And that’s been done without giving the WHO the money to do [the job properly].

“Member states need to take more responsibility for funding.”

Associate Professor Adam Kamradt-Scott, from the University of Sydney’s Department of Government and International Relations, said that in 2013 – just before the start of the Ebola crisis – the member states of the WHO had cut the organisation’s outbreak response budget by 51%. At the same time the Geneva headquarters cut staff in that department, anticipating that the regional offices would pick up the slack.

“That didn’t happen,” he said. “So by the time the Ebola outbreak began in March of 2014, there was a perfect storm brewing.

“The relationship between Geneva and the African office had [already] broken down.”

By the time the Ebola outbreak was building in the first half of 2014, the WHO was also dealing with three other Grade 3 emergencies – the most severe – in Syria, Central African Republic and South Sudan, each of which was an ongoing conflict categorised as Grade 3 in 2013.

Since the May 2014 World Health Assembly, the Ebola outbreak in West Africa (graded in July 2014), and the humanitarian crisis in Iraq (graded in August 2014) were added to the list.

The WHO decision not to declare a PHEIC in West Africa until 8 August 2014, thus delaying the release of financial and human resources to commit to the outbreak, was the most criticised part of the WHO response.

“A complicating factor was that in March 2014 it was originally thought to be an outbreak of Lassa fever,” A/Prof Kamradt-Scott told MJA InSight.

“It was identified as having a strong potential for cross-border transmission, but that was not communicated to Geneva.

“Additionally, the three countries involved – Sierre Leone, Liberia and Guinea – all told the May Assembly that they had the outbreak contained – essentially, they said ‘there’s nothing to see here’.

“You can’t blame the WHO Secretariat for that.

“That was just before there was a huge spike in cases – a doubling in number – that made it clear that the outbreak was not controlled.”

A/Prof Kamradt-Scott said it was unfair to say the WHO had not responded well between the start of the Ebola outbreak in March of 2014 and the declaration of the PHEIC on 8 August.

“That’s actually inaccurate”, he said. “They responded very forcefully. They sent 113 technical experts to Africa, when in the past the maximum sent would have been 2 to 5 individuals.”

Where the WHO ultimately failed was in believing Sierre Leone, Liberia and Guinea in May when they said the outbreak was under control, he said.

“Those countries are well known for their very poor disease surveillance and outbreak response. Geneva accepted what they said at face value and that was their biggest mistake.”

The Zika outbreak was a fluid and complex situation, all three experts agreed.

“There are a lot of unknowns still,” A/Prof Kamradt-Scott said. “We’ve [only recently] found out that Zika has been detected in saliva and urine, suggesting that it may be sexually transmittable; we still don’t know how long it can remain infectious.” The connection between Zika and microcephaly was also far from well established.

Control of the carrying mosquito was vital to how the outbreak progressed, he said.

“We have a very poor track record with controlling vector-borne diseases. The next 12 months will be quite critical.”